On Fri, 9 Feb 2018, Dave Hansen wrote: > Are there any straightforward rules that we can enforce here? For > instance, if you are using "page_type", you can never have PG_lru set. > > Not that we have done this at all for 'struct page' historically, it > would be really convenient to have a clear definition for when > "page_type" is valid vs. "_mapcount". Well in general we would like to be able to enforce uses depending on the contents of other fields in struct page. That would require compiler support I guess? What we could do is write a struct page validator that checks contents using some macros? Could be added to the usual places where we check consistency and could also be used for a global sweep over struct pages for validation. SLUB can do that for metadata. If we could express consistency rules for objects in general then it may even have a wider applicability. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>
